In telecommunications networks, signals are often transmitted from an input switch to multiple output switches, such as in data centers. Currently, switching cabinets are generally used to enable mutual communication among data center switches. However, an adapter cabinet of the related art includes two fiber optic connection backplanes, each of which is provided with a fiber connector, so that two switches can be connected through two fiber connectors. An improved adapter cabinet includes a fiber optic connection backplane with fiber optic connectors on the fiber optic backplane such that the two switches can be connected by one fiber optic connector. However, the above described adapter cabinets may experience large connection loss and require many components, which increases cost.